Respuesta :
Answer:
the whole turn is counterclockwise. and x = 0.40 m
Explanation:
This is a problem of rotational equilibrium so we will use the equation
Σ τ = I α
In this case alf is zero, the torque equation is
τ = F r
We will take the sense of counterclockwise rotation as positive.
Let's apply these expressions to our exercise.
We have the weight of the child that creates a right turn so it is negative and the force applied to the left of the pivot that creates a left turn the torque is positive
adult τ₁ = F x
child τ₂ = W x₂
τ₁ = 150 3
τ₁ = 450 N m
τ₂ = 20 9.8 2.0
τ₂ = 392 Nm
τ₁> τ₂
Here we see that the child's side turns in (goes up) and the adult's part goes down, the whole turn is counterclockwise.
Now the adult applies the force to a shorter distance (x = 2.0 m)
τ₁ = 150 2.0
τ₁ = 300 N m
τ₁ < τ₂
The direction of rotation is time, the adult goes up and the child goes down.
The last case the adult sits and asks the distance
W x = mg x₂
M g x = m g x₂
x = x₂ m / M
x = 2.0 20/100
x = 0.40 m
